The present invention relates generally to surgical instruments, and more particularly to a surgical instrument mount apparatus and surgical retractor system useful for positioning and securing a variety of instruments including tissue stabilizer devices for use during coronary artery bypass graft surgery.
Diseases of the cardiovascular system affect millions of people each year and are a leading cause of death throughout the world. The cost to society from such diseases is enormous both in terms of the number of lives lost as well as in terms of the costs associated with treating patients through traditional surgical techniques. A particularly prevalent form of cardiovascular disease is a reduction in the blood supply leading to the heart caused by atherosclerosis or other condition that creates a restriction in blood flow at a critical point in the cardiovascular system that supplies blood to the heart.
Treatment of such a blockage or restriction in the blood flow leading to the heart is, in many cases, treated by a surgical procedure known as a coronary artery bypass graft (CABG) procedure, more commonly known as a xe2x80x9cheart bypassxe2x80x9d operation. In the CABG procedure, the surgeon xe2x80x9cbypassesxe2x80x9d the obstruction to restore normal blood flow to the heart either by attaching an available source vessel to the obstructed target coronary artery or by removing a portion of a vein or artery from another part of the body, to use as a graft, and installing the graft between a point on a source vessel and a point on a target artery.
To restore the flow of blood to the heart, the CABG procedure requires that a fluid connection be established between two vessels. This procedure is known as an xe2x80x9canastomosis.xe2x80x9d Typically, a source vessel, such as a source artery with an unobstructed blood flow, i.e., the left internal mammary artery (LIMA), or a bypass-graft having one to end sewn to an unobstructed blood source such as the aorta, is sewn to a target occluded coronary artery, such as the left anterior descending (LAD) artery or other vessel that provides blood flow to the muscles of the heart.
Although the CABG procedure has become relatively common, the procedure itself is lengthy and traumatic and can damage the heart, the cardiovascular system, the central nervous system, and the blood supply itself. In a conventional CABG procedure, the surgeon makes an incision down the center of the chest, cuts through the sternum, performs several other procedures necessary to attach the patient to a heart-lung bypass machine, cuts off the blood flow to the heart and then stops the heart from beating in order to complete the bypass. The most lengthy and traumatic surgical procedures are necessary, in part, to connect the patient to a cardiopulmonary bypass (CPB) machine to continue the circulation of oxygenated blood to the rest of the body while the bypass is completed.
In recent years, a growing number of surgeons have begun performing CABG procedures using surgical techniques especially developed so that the CABG procedure could be performed while the heart is still beating. In such procedures, there is no need for any form of cardiopulmonary bypass, no need to perform the extensive surgical procedures necessary to connect the patient to a cardiopulmonary bypass machine, and no need to stop the heart. As a result, these beating heart procedures are much less invasive and the entire procedure can typically be achieved through a small number, typically one or two, comparatively small incisions in the chest.
Despite the advantages, the beating-heart CABG procedure is not universally to practiced, at least in part, because of the difficulty in performing the necessary surgical procedures using conventional surgical instruments. For example, it has been difficult for the surgeon to access the required areas of the heart requiring revascularization. In addition, the various surgical steps that are required to be performed on the heart itself are more difficult to perform because the heart muscle continues to move and contract to pump blood throughout the duration of the procedure.
The specific portion of the surgical procedure that creates the anastomosis in the beating-heart CABG procedure is particularly difficult. Completion of the anastomosis requires placing a series of sutures through extremely small vessels on the surface of the heart while the heart muscle continues to beat. Moreover, the sutures must be carefully placed to ensure that the source vessel or graft is firmly attached and will not leak when blood flow through the vessel is established. In cases where the target coronary artery is temporarily obstructed, for example, to improve the surgeon""s visibility and avoid excessive blood loss, it is also important that the anastomosis procedure be performed rapidly to avoid ischemic damage to the heart.
Further adding to the difficulty of the procedure is the fact that the working space and visual access are often quite limited. The surgeon may be working through a small incision in the chest, for example, or may be viewing the procedure on a video monitor if the site of the surgery is viewed via surgical scope. The vessel, and particularly the arteriotomy to which a source vessel is to be anastomosed, may also be very difficult for the surgeon to see as it may be obscured more or less by layers of fat or other tissue.
The beating-heart CABG procedure could be greatly improved if the heart could be accessed and stabilized during the procedure such that the motion of the heart, particularly at the site of the anastomosis, is minimized even though the heart continues to beat and supply blood to the body. The beating-heart CABG procedure could be-further improved if the target vessel, and specifically the arteriotomy was presented to the surgeon in a way that allows sutures to be easily placed.
In view of the foregoing, it would be desirable to have improved devices for accessing and effectively stabilizing the beating heart at the site of the anastomosis. It would be desirable to have a retractor system that provides unobstructed and organized access to the areas of the heart requiring revascularization. It would be further desirable to have a low-profile, a traumatic stabilizing device that stabilizes the beating heart at the site of the anastomosis and provides a favorable presentation of the target vessel and the arteriotomy. It would be further desirable to provide a mount for the stabilizing device, or other instruments, that allows the stabilizing device to be easily maneuvered to the desired position and orientation, fixedly secured until the procedure is completed, and then easily removed from the site of the anastomosis.
The present invention will be generally described for use in performing CABG surgery, but the invention is not limited thereto, and is contemplated to be useful for other surgical procedures requiring surgical instruments to be positioned and secured through an incision into a patient.
The present invention involves various aspects of an instrument mount useful for positioning and securing surgical instruments, for example, during a CA procedure on a beating heart. One aspect of the present invention involves a low-profile, flexible, right-angle instrument mount for maneuvering and securing a wide array of surgical instruments.
One aspect of the present invention involves an instrument mount apparatus for positioning a surgical instrument comprising a mount body having a base portion moveably coupled at a first articulating joint and a side portion moveably coupled at a second articulating joint, the first and second articulating joints being freely moveable when in an unlocked condition and substantially immovable when in a locked condition which may be accomplished through manipulation of a single actuator.
The actuator may include a base post assembled thorough the base portion and the mount body arid interconnected at a first end to a cam operatively interfacing a contact surface on the mount body, and a tie pin having a slotted portion which receives the base post. Operation of the cam draws the base post toward the cam and into a locked position. A ramped portion of the base post drives the tie pin into the locked position.
A grip member may be included, which forms an opening with the side portion for receiving a surgical instrument. The tie pin may be connected, at a first end, to the grip member, preferably by a pair of flexible prongs. Movement of the tie pin to the locked position draws and locks the grip member against the side portion and also locks the second articulating joint.
The tie pin may further be releasably connected to a release button at a second end, such that pressing of the release button extends the tie pin and grip member to allow removal of the grip member to exchange surgical instruments.
Preferably, the first articulating joint is at an angle relative to the second articulating joint. The angle between the first and second articulating joints is typically less than about 130 degrees, more typically less than 120 degrees. In a preferred embodiment, the angle is between about 100 degrees and about 45 degrees, most preferably about 90 degrees.
The articulating joints may be any mechanical configuration which provides the desired degrees of freedom for maneuvering a surgical instrument. Preferably, the first articulating joint comprises a ball-type joint or a ball and socket joint. The ball and socket joint may comprise a ball-shaped member extending from the base portion and a to cooperating socket formed within the mount body. The second articulating joint may preferably comprise a ball and socket joint or a rotational joint. When the second articulating joint is configured as a rotational joint, it may comprise a frustoconical member extending from the side portion and a cooperating frustoconical cavity within the mount body.
The side portion and the base portion may include a number of other features or structures connected thereto for a variety of purposes which take advantage of the movement of the side portion relative to the base portion provided by the articulating joints. For example, the side portion may further include a grip member. The side portion and the grip member may be positioned to form an opening therebetween for receiving a surgical instrument. The grip member may have an unlocked condition relative to the side portion wherein the opening allows relatively free movement of the surgical instrument and a locked condition wherein the grip member and the side portion are forced together to lock the instrument against relative movement.
The base portion may be adapted to cooperatively engage a rail member. The rail member may generally have a T-shaped cross-section. In a preferred embodiment, the rail has a top portion and a bottom portion, the bottom portion having a narrowed region adjacent the top portion forming first and second tabs on the top portion and the base portion further comprises first and second hooks adapted to engage the first and second tabs. Preferably at least one of said hooks is moveable relative to the other to allow the base portion to lock onto and release from the first and second tabs. The rail is preferably fixed or otherwise associated with a sternal or rib retractor.
Another aspect of the present invention involves an instrument mount apparatus for positioning and securing a surgical instrument which includes a mount body having a base portion moveably coupled at a first articulating joint and a side portion moveably coupled at a second articulating joint. A post preferably extends through the first articulating joint along a first axis and has a first end portion engaging the base portion. A pin preferably extends through the second articulating joint along a second axis and has an end portion engaging the side portion and a threaded portion. A knob is may be provided having an internal bore for receiving at least a portion of the pin, the internal bore having threads adapted to engage the threaded portion of the pin. The knob may preferably have a thrust surface associated therewith adapted to engage and move the post as the knob traverses over the threaded portion of the pin in response to rotation of the knob.
Again, the articulating joints may be any mechanical configuration which provides the desired degrees of freedom for maneuvering a surgical instrument. Preferably, the first articulating joint comprises a ball-type joint or a ball and socket joint. The ball and socket joint may comprise a ball-shaped member extending from the base portion and a cooperating socket formed within the mount body. The second articulating joint may to preferably comprise a ball and socket joint or a rotational joint. When the second articulating joint is configured as a rotational joint, it may comprise a frustoconical member extending from the side portion and a cooperating frustoconical cavity within the mount body.
The post may preferably further comprises a cam surface positioned to mate with the thrust surface, whereby rotation of the knob along the threaded portion causes translation of the thrust surface in a direction along the second axis, the thrust surface engaging the cam surface to move the post in a direction generally along the first axis. The knob may include a first end adapted to be grasped by a user and a housing end adapted to be received within the mount body. The thrust surface may be located on the housing end of the knob. In another configuration, the thrust surface may be provided on a lift member which is slidable along the second axis. The lift member may have a first end having the thrust surface and a second end. The housing end of the knob is preferably positioned to engage the second end of the lift member such that when the knob is traversed along the second axis, it engages the lift member which causes the thrust surface to engage the cam surface thus causing the post to move along the first axis.
When the post is urged in a first direction along the first axis, the first articulating joint preferably becomes locked. When the first articulating joint is a ball and socket joint formed between a ball extending from the base portion and a socket formed within the mount body, the ball and socket become locked by operation of the first end of the post which engages the base portion and forces the two together as the post is urged upwards. When the post moves in the opposite direction, the articulating joint returns to a condition which allows relatively free articulation. A second end of the post is may be constrained within a top opening provided in the mount body. Preferably, the second end is slidable within the top opening generally along the first axis.
These and other features of the present invention will become more fully apparent from the following description and appended claims.